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vectors.md

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Vectors

Create a Vector

To create immutable instances use:

val immutableV2 = vec2(1f, 2f)
val immutableV3 = vec3(1f, 2f, 3f)
val immutableV4 = vec4(1f, 2f, 3f, 4f)

To create mutable instances:

val mutableV2 = mutableVec2(1f, 2f)
val mutableV3 = mutableVec3(1f, 2f, 3f)
val mutableV4 = mutableVec4(1f, 2f, 3f, 4f)

Create functions called without parameters return zero vectors:

val immutableV2 = vec2() // (0.0, 0.0)
val immutableV3 = vec3() // (0.0, 0.0, 0.0)
val immutableV4 = vec4() // (0.0, 0.0, 0.0, 0.0)

The same is true for mutable vectors:

val mutableV2 = mutableVec2() // (0.0, 0.0)
val mutableV3 = mutableVec3() // (0.0, 0.0, 0.0)
val mutableV4 = mutableVec4() // (0.0, 0.0, 0.0, 0.0)

Dedicated functions introduced to create unit vectors:

val immutableUnitX = vecUnitX() // (1.0, 0.0)
val immutableUnitY = vecUnitY() // (0.0, 1.0)
val immutableUnitZ = vecUnitX() // (0.0, 0.0, 1.0)
val immutableUnitW = vecUnitW() // (0.0, 0.0, 0.0, 1.0)

Copy a vector

There is also a way to create a copy of an existing vector. Please notice, that copy of immutable vector is the same instance

// immutableVec === immutableCopyVec
val immutableCopyVec = immutableVec.copyOf() 

// mutableVec == mutableCopyVec but mutableVec !== mutableCopyVec
val mutableCopyVec = mutableVec.copyOf()

You can also use creation functions to change vector dimensions:

val immutableV2 = vec2(1f, 2f)                // (1.0, 2.0)
val immutableV3 = vec3(immutableV2, 3f)       // (1.0, 2.0, 3.0)
val immutableV4a = vec4(immutableV3, 4f)      // (1.0, 2.0, 3.0, 4.0)
val immutableV4b = vec4(immutableV2, 3f, 4f)  // (1.0, 2.0, 3.0, 4.0)

And for mutables

val mutableV2 = mutableVec2(1f, 2f)              // (1.0, 2.0)
val mutableV3 = mutableVec3(mutableV2, 3f)       // (1.0, 2.0, 3.0)
val mutableV4a = mutableVec4(mutableV3, 4f)      // (1.0, 2.0, 3.0, 4.0)
val mutableV4b = mutableVec4(mutableV2, 3f, 4f)  // (1.0, 2.0, 3.0, 4.0)

There is a conversion between mutables and immutables:

val immutableFromMutableVec = mutableVec.toImmutable()
val mutableFromImmutableVec = immutableVec.toMutable()

Get a Vector Length

To calculate Euclidean vector length:

val length = vec.length()

or square of the length:

val sqrLength = vec.sqrLength()

Get a distance Between Two Vectors

In a common sense the distance between two vectors a length of their subtraction, but there is a more convinient wat to get the distance:

val distance = vecA.distance(vecB)
val sqrDistance = vecA.sqrDistance(vecB) // Returns a square of the distance

Get a Dot Product

val dotProduct = vecA.dot(vecB)

Mutate Vectors

It is allowed to modify each vector component by its names (x, y, z, w):

mutableVec4().apply {
    x = 1f
    y = 2f
    z = 3f
    w = 4f   
}

or set values in a single call:

mutableV2.set(1f, 2f)
mutableV3.set(1f, 2f, 3f)
mutableV4.set(1f, 2f, 3f, 4f)

if you want to set same value to each component use setAll():

mutableV2.setAll(5f) // (5.0, 5.0)
mutableV3.setAll(5f) // (5.0, 5.0, 5.0)
mutableV4.setAll(5f) // (5.0, 5.0, 5.0, 5.0)

Negate vector

// Create a new mutable instance holding the result
val mutableVec = vec.negate()
// Put the result to mutableVec and return it
// mutableVec === negatedMutableVec
val negatedMutableVec = vec.negateTo(mutableVec)
// Perform the operation in-place
// mutableVec === negatedMutableVec
val negatedMutableVec = mutableVec.negateSelf()